Magnetic chuck.



F. L. SIMMONS.

MAGNETIC CHUCK. APPLICATION FILED NOV. 5. 1914.

Patented Jan. 29, 1918.

' STATS FRANK L. SIMMONS, 0F MILLBURY, MASSACHUSETTS, ASS-1 11101? T0 THE TAPE-191 351 MANUFACTURING COMPANY, OF'WOONSOCKET, BHODE ESLAND, A fifiltitfc filtffiift ll OF'BHODE ISLAND.

MAGNETIC CHUCK.

Specification of Letters Patent.

Application filed November 5, 1914. $eria1 No. 870,51t1.

together with the accompanying drawings,

is a specification.

The present invention relates to a magnetic chuck, having a work supporting surface adapted to retain the iron and steel pleoes of work in fixed position, to be operated upon by the machine with which the chuck- 1S used. The invention consists in the construction and arrangement of parts set forth in detail in the following description, and particularly pointed out in the claims annexed-thereto, by means of which a chuck having a greater holding power, and no ap-- preciable leakage of the lines of magnetic force, is produced.

In the accompanying drawings,

Figure 1 is a top plan view of a chuck embodying my invention.

Fig. 2 is a vertical sectional view on line 2-2, Fi 1.

Fig. 3 is aside view of the chuck with the.

detachable side plate removed to disclose the interior construction.

Like reference characters refer to like parts throughout the different figures.

Referring to Figs. 1, 2-and 3, 1 indicates a rectangular metallic frame, inclosing be tween its ends 2, 2 and its sides 3, 3 a rectan ular space which is divided by a cross bar 1- parallel with the sides 3, 3. The two spaces thus formed on opposite'sides of the cross bar 4 are adapted to be filled by the pole pieces of the chuck in the manner hereinafter set forth; in the present instance I have shown a construction in which said pole pieces, constituting the work holding face of the chuck, are disposed longitudinall with respect to the longest dimension of t e rectangular frame 1; it will be clear, however, that the length of the chuck between the ends 2, 2, of the frame can be increased indefinitely by the addition of similarly disposed ole pieces, whereby a chuck having pole pieces extending longitudinally of the shortest dimension of the frame is produced.

In the construction of said frame 1, the sides 3, 3, and the crossbar 1 are formed with oppositely facing horizontal flanges 5,

providing steps or shoulders for the support of the ends of pole pieces 6, which are .shaped to overhang said shoulders when disposed in assembled relation within said frame. i

The several pole pieces 6, herein shown as eight in number, four on each side of the cross bar 4, although it isclear that any number of such pole. pieces may be provided, are disposed side by side in rows, and in conjunction with their interposed gaps of non-magnetic metal, hereinafter more specifically referred to, entirely fill the two spaces inclosed by the sides and ends of the frame 1, thereby forming, entirely by them selves, the work holding face of the chuck.

Adjacent pole pieces of each row are adapted to be energized to be of opposite magnetic polarity, and to this end each pole piece 6 is formed with an integral depend ing shank 7 having an outwardly extending lateral boss 8. Said bosses 8, disposed in rows below and inwardly oft-he sides 3 of the frame 1 constitute cores, for the support of the energizing coils 9, each of which is mounted in surrounding relation to one of said bosses, as shown in Fig. 3.

As also shown in said Fig. 3, the ends 2, 2, of the frame 1 have integraldownward extensions 10, 10, forming end walls between which the two rows of alined shanks 7, bosses 8 and coils 9 are disposed. Prefer ably, the ends 2, 2, of-the frame slightly overhang their integral extensions 10, 10, as shown at 11, 11, Fig. 3'. in assembling the parts of the structure thus far described, the frame 1 with the pole pieces 6 loosely inserted therein, is disposed in an inverted position, with the upper faces of said pole pieces resting on a true plane surface. The gaps 12 between adjacent pole pieces, and between said pole pieces and the sides and ends of the frame, are filled with a non-magnetic substance, such as Babbitt metal, poured therein from the interior of the space inclosed between the end walls 10. The pole pieces are thereby firmly locked in position, and are incapable of movement in said frame, being supported at their ends by the flanges 5.

In practice it is found desirable to form the longitudinal edges of the pole pieces with interlocking projections and recesses 13 and 14 respectively, as shown in Fig. 1, the inner edges of the ends 2 of the frame being correspondingly shaped to conform to the edges of the two end pole pieces of each row. In this manner, the actual length of the gaps 12 is increased and the same are brought into closer proximity at certain portions of the work holding face of the chuck than would be possible if an equal number of 'pole pieces, with straight longitudinal edges, were employed.

After the disposal of the coils 9 upon their respective cores, and the proper connection of said coils with a source of electrical supply to impart opposite magnetic polarity, to adjacent cores'of the series, a thin steel plate 15 terminating short of the opposite end walls 10, is placed in contact with the outer faces of thecores 8 of each row, and is secured thereto by screws 16,

thereby retaining all the coils 9 in position upon said cores. Thereafter plates 17 of brass or other non-magnetic material are disposed onthe outside of said steel plates, being suitably secured thereto by pins 18 or the like.

Said brass plates "serve to interpose a nonmagnetic gap between said steel plates 15 and the detachable side plates 19 of the chuck, which coiiperate with the end walls -10 in completing theinclosure of the cores 8 and coils 9. Said side plates 19 are of such a thickness that the sides 3 of the frame 1 will slightly overhang, when the said plates are brought into abutting relation with the brass plates 17 and the vertical edges of the end walls 10, which have been finished simultaneously to present a true surface for the attachment of said plates. Said end walls 10 have suitable threaded holes 20 to receive screws passed through the plates 19 to hold them firmly in position. When the plates 19 are in position, the lower edges of the same and the lower edges of the end walls 10 are finished simultaneously, in order to present a true surface for the attachment of a plate 21 forming the bottom of the chuck, by means of screws 22 passing into lateral flanges 23 of said end walls.

If desired, blocks 24 of Babbitt metal or other non-magnetic substance, may be inserted between said plate21 and the lower ends of the shanks 7 of the pole pieces, brass screws 25 being used to rigidly unite the i parts, while at the same time preventing the flow of magnetic lines of force between them.

It will be apparent that ll'have provided a chuck capable of exerting a powerful holding force on any work which is disnear.

posed to bridge any of the gaps 12 between adjacent pole pieces 6 of its work holding face. Said face is constituted entirely by the pole ieces 6, and is entirely free of dead spaces. 'lhe possibility of leakage of mag netic lines of. force from the cores 8 to. any portion of the shell or housing of the chuck is largely eliminated by the use of the brass plates 17 and the Babbitt blocks 24. Furthermore, the integral construction of the pole pieces 6 and their respective cores 8 insures the transmission of the full magnetic force to the face of the chuck, without possibility of leakage, due to the use of more or less perfectly ground joints between the separate pole pieces and core members ordinarily provided. lhe easily removable side plates 19 furnish direct access to the electrical connections and'the coils 9, making the replacement or repair of the same an exceedingly simple proposition.

Features of my invention herein disclosed but not herein claimed, are claimed in my continuing application Serial No. 120,189, filed Sept. v1 1, 1916.

I claim,

1. A magnetic chuck having a work holding face constituted by a plurality of oppositely energized individual pole pieces, each of said pole pieces having a laterally extending core, and a coil disposed vertically upon each corc, whereby to be exposed by the re- .moval of the side wall of the chuck.

2. A magnetic chuck comprising a housing or shell, a work holding face constituted by a plurality of individual oppositely energized polegiieces having portions depending within sai housin or shell, lateral projections on said depenc ling portions arranged in arow along one side of the chuck, and coils dlsposed upon said projections for exposure by the removal of one of the sides of said housing or shell.

3. A magnetic chuck comprising a housing or shell, open at its upper end, a detachable face plate, comprising a frame superposed on said shell, and a plurality of individual oppositely energized pole pieces, extending in a row from side to side of said frame with theirlends supported thereby, and'a core depending from each pole piece, within the space inclosed by said shell.

Dated this third day of November 1914.

FRANK lL. SIMMONS.

Witnesses:

PENELOPE CoMBEaEAoK,

NELLIE WHALEN. 

